One of the main issues with KVO is caused by classes not knowing what observers a superclass has registered.
When a subclass also wants to observe the same keyPath they have the danger of removing the observer from the super class.

__attribute((objc_requires_super)) was first introduced as work in progress into CLANG in September 2012 and was documented in October 2013. On both OS X and iOS there is now a NS_REQUIRES_SUPER macro that conditionally wraps the objc_requires_super attribute depending on compiler support. Once a

After having promised to have LTE available by the end of 2013, today was the day that my account was finally enabled for LTE on Three. While the mast near my home has not yet been upgraded for LTE. The wait was definitely worth it.

Recently a GitHub project has been published that aims to introduce custom literals to Objective-C. The syntax is simple: $(#FF0000) would return [UIColor redColor] while $(null) could return NSNull. It also allows classes to register their own mapping. Full details can be found on Dustin